History of ICDD

Brief History of the ICDD

After the development of the first X-ray powder diffraction techniques
in the first part of the twentieth century, the need for a central
collection of diffraction patterns from known phases became apparent. Following
the publication of two landmark papers in the late 1930s on the archiving and use of powder data for phase
analysis by Dow scientists, the Joint
Committee for Chemical Analysis by Powder Diffraction Methods was founded
in 1941. They produced a primary reference of X-ray powder diffraction data,
which became known as the Powder Diffraction File™ (PDF). This effort
was initially supported by Committee E-4 of the American Society for
Testing and Materials (ASTM). Over the next two decades, other
professional bodies added their support, culminating in 1969 with the
establishment of the Joint Committee on Powder Diffraction Standards (JCPDS).
The JCPDS was incorporated to continue the mission of maintaining the PDF.
In 1978, the name of the organization was changed to the International
Centre for Diffraction Data in order to highlight the global commitment of
this scientific endeavor.

The ICDD Organization

Approximately 300 scientists from around the world comprise the active membership from
which the organization draws its Board of Directors, committees, and subcommittees. The members, who are
volunteers, are actively engaged in developments in the field of X-ray powder diffraction
and related disciplines. Membership consists of
scientists from various affiliations - educational, governmental, and industrial.
Semi-annual meetings of the members provide a forum for the exchange of ideas and
information pertinent to the scientific community and to organize, plan, and review
policies and procedures within the ICDD organization. A paid scientific and administrative staff, located at the Newtown Square, Pennsylvania Headquarters,
is responsible for the production and distribution of the various databases offered by the
ICDD.

The Powder Diffraction File™

The Powder Diffraction File™ (PDF) is a collection of
single-phase X-ray powder diffraction patterns in the form of tables of characteristic
interplanar spacings and corresponding relative intensities along with other pertinent
physical and crystallographic properties. The creation, maintenance, and dissemination of
such a file was the primary purpose for the establishment of the ICDD and its predecessor
organizations. Annual supplements to the File each contain approximately two thousand
patterns.

In order to meet the individual need of diffractionists worldwide, the Powder
Diffraction File™ is available on a variety of media - books, CD-ROM, and DVD.
The PDF has various subfiles of data which include, but are not limited to, minerals,
metals and alloys, and forensic materials. There is also an educational package for classroom use. Various methods,
including the use of printed indexes and computer software, enable users to match data in
the File with their laboratory data.

Data Acquisition for the PDF™

Data for the publication in the Powder Diffraction File™ are acquired through
contributions from individual scientists, corporate laboratories, literature surveys, and
a Grant-in-Aid program. Approximately 200 leading
scientific journals are searched manually for powder diffraction data. Additional
literature surveys covering patents, dissertations, and the remaining open literature are
performed utilizing various online databases and search techniques.

PDF Quality Assessment

All data are critically reviewed and evaluated by the editorial staff. Each pattern
must pass through a four-tiered editorial review process before it can be included in the
PDF. As technology evolves, the quality requirements for reference pattern data also
evolve. As a result, information in the PDF is continuously reviewed and upgraded for
accuracy and quality.